STUDY OF YIELD POTENTIAL OF MAIZE SIMPLE HYBRIDS IN CYCLIC CROSS SYSTEM PUBLISHEDAndreea ONA1, I. HAȘ1,2, Voichița HAȘ2, Rodica POP1
Maize has an important role in the Romanian agriculture, as a result of its multiple uses and optimal conditions from our country. According to the National Institute of Statistics, in the year 2011, the area cultivated with maize in Romania was of 2.613.500 hectares, with a total production of 11.666.400 tonnes of grains, placing our country on the 1st place in the European Union for the area cultivated with maize and the 2nd place for production, after France, due to an inferior yield. Otherwise, the maize yield achieved by Romania is smaller than the one achieved by the other Member States, with only 4464 kg/ha grains beside the average from the European Union of 6902 kg/ha. Yield potential can be considered genetically, the most complex characteristic. We can appreciate that the heredity of this trait is the expression of the entire genetic system of the plant, which directly or indirectly controls all fundamental involved processes (metabolic, growth and development). This paper presents the obtained results of the maize experiments fields conducted at Agricultural Research and Development Station Turda, using simple hybrids in cyclic cross system, between 2011-2012. The objectives of this paper are to highlight the genic effects involved in the heredity of the production capacity at the hybrids derived from crossings of inbred lines resulted by inbreeding, from commercial hybrids, with inbred testers, from Lancaster heterotic group. The analysis of variance for grain yield indicates significant differences between the tested maize hybrids. Comparing the general combining ability of the tested lines, reveals significant differences, the tester inbred lines being from the Lancaster germplasm group and the tested inbred lines from other heterotic groups. Also, were highlighted the effects of the specific combining ability. The effects values for the general combining ability (GCA) of the testers ranged from -85 kg/ha to +143 kg/ha. At the tested inbred lines, the value ranged between -508 kg/ha and +1141 kg/ha. The effects for the specific combining ability (SCA) was between -669 kg/ha and +589 kg/ha. Between inbred lines used as testers, production differences are not statistically significant. Among the tested inbred lines, the highest achieved average production in crosses with three testers, conducted to TA 452. The average yield was 9550 kg/ha and the additive effects for this line production capacity were, for this experimental system, of 1141 kg/ha. Regarding to the inbred lines obtained from Raissa hybrid, the highest production capacity from this experimental system was transmitted by TE 317. Our results highlight that in the production potential heredity are involved, mainly, the additive genic effects, but the non-additive genic effects are also important.
yield potential, general combining ability, specific combining ability.